Effects of crease angles and defects on membrane tensile behavior

In this study, the mechanical behavior of creased membrane structures under uniaxial tensile tests is investigated after deployment, focusing on the effects of crease formation, crease angles, and induced defects. The results show that crease introduction reduces the fracture strain, although the fracture strength of creased and uncreased membranes remains similar. Moreover, the local elastic modulus of the creased region along the unfolding direction is found to be 69.5% of that of an ideal pure membrane based on the determination of crease influence width. The analysis of crease angle reveals that both fracture strength and strain increase with crease angle. For membranes with a 90°crease, the fracture strength is about 10.9% higher than that of the membrane with a horizontal crease. The elastic modulus in the direction of crease extension and shear modulus can be determined and verified through mechanical testing and finite element analysis of the angled creased membranes, forming an orthotropic elastic parameter model for the creased region. Finally, the introduction of circular holes of various sizes as geometric defects significantly affects wrinkle distribution and out-of-plane deformation, while notably reducing fracture strain and fracture stress, with the impact on fracture strain being particularly pronounced. This study offers crucial insights into the design of creased membranes, particularly for aerospace and space exploration, where performance under complex loading and defects is critical.